1. Field of the Invention
The invention relates to a game apparatus and a game program. More specifically, the present invention relates to a game apparatus and a game program which allow a player to play a game by adding a motion to a controller itself by the player.
2. Description of the Related Art
One example of a game apparatus of such a kind is disclosed in a nonpatent literature 1 (http://www.nintendo.co.jp/wii/controllers/index.html). In the related art, “Wii remote controller” (Wii: registered trademark) has a three-axis acceleration sensor for detecting changes of tilts and motions of itself. “Nunchaku” also has a three-axis acceleration sensor.
In order to perform the game on the outputs from the three-axis acceleration sensors, the player perform an operation by swinging and tilting the Wii remote controller and the Nunchaku while holding the Wii remote controller with one hand and the Nunchaku the other hand.
In the aforementioned nonpatent literature 1, since the acceleration sensor is used, the change of the attitude of the controller can be determined by the gravitational acceleration, but there is a problem of being unable to detect the rotation about a yaw direction, that is, in the direction of the gravitational force. Furthermore, if acceleration other than gravity is highly applied, there is a problem of being unable to accurately calculate the orientation.